Assessment of Causes and Effects of Variation on Construction Project Performance in South West Nigeria

The construction industry in Nigeria faces many problems, including the delay due to variations in project execution. This delay has been studied as a major setback in the Nigerian construction industry. In Nigeria, the construction industry's performance in terms of time has been observed to be poor. The objective of this study is to examine the variation of the construction project in order to determine the effect on the delivery of the project. The maximum performance of the project would be reached if the work always goes efficiently on time with the budget. The result of the variation is delay, cost overruns, quality defects and other negative impacts. The causes of variation were identified by a questionnaire survey for two higher education institutions. The results of the study identified the five main factors, including change of plan or scope, defective labour, customers' financial problems, unavailability of skills and desired profitability of the entrepreneur. In general, the study shows agreement among clients, consultants and contractors regarding the classification of the 20 factors that cause the variation. The results also reveal that factors related to clients are the main causes of variation, followed by factors related to contractors. An understanding of the causes and effects of the variation would be helpful in training professionals to assess the variation. In addition, the study would also help professionals take proactive measures to reduce the gaps on construction projects.